The objectives of this study were to assess the effects of supplementation of Astragalus membranaceus root powder (AMP) and AMP processed to different particle sizes on growth performance, antioxidant status, and serum metabolites of broiler chickens. The experiment was conducted with one hundred twenty 1-d-old Arbor Acres broilers in 5 groups of 4 cages and for both starter (0 to 21 d) and grower (22 to 42 d) phases. The treatments were basal diet only (control) and basal diet supplemented with 5 g/kg of diet of AMP processed to particle sizes of 300, 149, 75, or 37 µm. Average daily gain, ADFI, and feed conversion rate (FCR) were determined weekly, and carcass yield, serum antioxidant enzyme activity, and metabolites were determined at 21 and 42 d of the experiment. Supplementation of AMP increased (P < 0.01) activities of total superoxide dismutase (TSOD) and glutathione peroxidase (GSHPx), but reduced (P < 0.01) concentrations of malondialdehyde (MDA) and cholesterol in the serum of chickens at 21 and 42 d. Reducing AMP particle sizes from 300 to 37 µm linearly increased (P < 0.01) TSOD and GSHPx activities at 21 and 42 d, but linearly decreased (P < 0.01) MDA at 42 d. Concentrations of total protein, albumin, and globulin in the serum were also increased (P < 0.05) or tended to be increased (P = 0.05 to 0.10) by AMP and linearly increased (P < 0.01) as the AMP particle sizes decreased. However, both treatments had no effect on ADG, ADFI, or FCR throughout the entire experiment period, although carcass yield increased (P < 0.05) at 42 d. Dietary supplementation of AMP at the concentration of 5 g/kg of diet enhanced serum antioxidant status and its efficacy linearly increased as the AMP particle size decreased from 300 to 37 µm, but had no effect on growth performance of broilers.

Effects of dietary δ-aminolevulinic acid (ALA) supplementation on serum iron status, blood characteristics, egg production and quality were examined in laying hens in an 8-week feeding trail. Two hundred and forty (Hy-line brown, 40-week-old) layers were randomly assigned to four dietary treatments with ten replications (six layers in adjacent three cages). Dietary treatments included: 1) CON (basal diet), 2) ALA1 (CON+ALA 5 ppm), 3) ALA2 (CON+ALA 10 ppm) and 4) ALA3 (CON+ALA 15 ppm). All nutrient levels of diets were formulated to meet or exceed NRC (1994) recommendations for laying hens. During the entire experimental period, differences of serum iron concentration and total iron binding capacity (TIBC) were significantly increased in ALA1 supplemented treatment (quadratic effect, p<0.05). The difference of total protein between 8 and 0 weeks was significantly higher in ALA2 treatment than CON treatment (quadratic effect, p<0.05). No significant effects were observed on hemoglobin, WBC, RBC, lymphocyte and albumin concentrations. Egg production and egg weight were not influenced by the ALA supplementation. Egg yolk index was also significantly higher in ALA3 treatment than CON treatment at the end of 4 and 8 weeks (linear effect, p<0.05). Haugh unit was increased in ALA3 treatment compared to CON and ALA1 treatments at the end of 8 weeks (linear effect, p<0.05). However, egg shell thickness, breaking strength and yolk color unit were not affected by the ALA supplementation. In conclusion, dietary ALA supplementation at a level of 5 ppm can affect iron concentration in serum while higher levels (10 or 15 ppm) have some beneficial influences on blood profiles and egg quality.

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This study was conducted to evaluate the effects of mineral and vitamin-enhanced supplementation on egg production, egg quality and concentrations of calcium and phosphorus in serum of spent laying hens. A total of 240 (72-wk-old) Hy-line brown commercial hens were used in the current trial for 4 weeks. Dietary treatments included 1) CON (basal diet), 2) ESS1 (basal diet + Egg shell strengthen 0.1%), 3) ESS2 (basal diet + Egg shell strengthen 0.2%) and 4) FESS (basal diet + Fe egg shell strengthen 0.2%). During the overall period, egg production was increased in CON and ESS2 treatments compared with ESS1 treatment (P<0.05). Egg shell breaking strength and final egg shell thickness were significantly higher in ESS2 treatment than CON and FESS treatments (P<0.05). Egg yolk color index was significantly lower in ESS1 treatment than other treatments (P<0.05). Moreover, Haugh unit was significantly lower in ESS1 and FESS treatments than CON treatment (P<0.05). Mineral-and vitaminenhanced supplementation did not affect either egg shell color or calcium and phosphorus concentration in serum. In conclusion, mineral-and vitamin-enhanced supplementations of laying hens diet are helpful in improving egg shell breaking strength and thickness by supplementation of Egg shell strengthener 0.2%.(Key words : mineral, vitamin, egg shell quality, egg shell strengthen, spent laying hens) † To whom correspondence should be addressed : inhokim@dankook.ac.kr